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How does a heat pump work in winter?

How does a heat pump work in winter? (Explained!)

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    You may be curious to know how heat pumps or air conditioners work in the winter to heat your room. Here’s the answer.

    The heat pump can reverse its mechanism to heat the room. In this procedure, the compressed refrigerant (which remains hot) gets circulated inside the room through the indoor unit. And the decompressed refrigerant gets circulated in the outdoor unit, which remains cold. 

    It’s just the reverse task that an AC does to make your room cool.

    Using a heat pump in winter is better than using a furnace or an electric heating system cause they are comparatively

    • Power Efficient
    • Fast Working, and
    • More comfortable due to the sensitive temperature adjustability

    How does a heat pump heat a house in the winter?

    In winter, the heat pump works in four principal steps. Before writing them, let me explain the main components of a heat pump.

    Main parts of a heat pump

    A. Indoor Unit

     The indoor unit is the part of the air conditioner that remains inside your room. It might be the front side of the machine, which you’ll find on a window-type air conditioner. Or it might be a separate unit that you may find on a split-type air conditioner.

    The indoor unit contains metal fins, and the copper-built capillary tube remains in a coil shape inside those fins.

    B. Outdoor Unit

    The outdoor unit is called the condenser and remains outside the room. Though in window type ac, the condenser unit remains at the rare side of the unit, and in portable ac, the condenser remains at the bottom portion.

    The condenser unit has two core parts. 

    • The Compressor
    • The Copper built Capillary Tube with fins.

    Similar to the indoor unit, the condenser has metal fins that contain copper tubes in a coil shape.

    C. Compressor

    The compressor is the heart of the heat pump. The condenser unit holds the compressor, and it contains the refrigerant gas.

    The heat pump’s working steps during the winter.

    The following cycle occurs when you choose the “Heating” Mode at your remote control or the thermostat in winter. 

    Step 1: First, the compressor starts spinning reversely. So the compressor starts compressing the refrigerant gas; thus, the gas temperature rises to about 120°F~140°F. Then the hot liquid refrigerant starts circulating through the indoor unit’s copper tubes.

    Step 2: In this step, the fan or blower of the indoor unit blows air forcefully through the metal fins, so the air remains hot, getting in touch with the copper tube. Thus the temperature of refrigerant slightly falls to 90°F.

    Step 3: The comparatively lower-temperature gas comes to the outdoor unit and starts getting decompressed. Thus the gas temperature falls near 0°F or (-18°C). This chilled gas starts circulating through the outdoor unit.

    Step 4: Finally, the outdoor fan blows air through the fins, and the chilled gas starts gaining a temperature near 60°F. Then the warm refrigerant again circulates for compressing cycle.

    This is how the heat pump works during the winter.

    My Fabourite Heat Pump that You can Use in Winter [BLACK + DECKER]

    How does a pool heat pump work in winter?

    A pool heat pump works in the exact mechanism that I have already described. But instead of blowing air to spread the heat, the water circulation distributes the heat to the pull. The steps are described below.

    Step 1: The refrigerant gas gets compressed by the compressor and distributed toward the water circulation unit. Here the gas temperature remains around 120F ~ 140F.

    Step 2: Due to the water circulation, the gas temperature gets distributed to the pool water, and the gas temperature falls near 90F. Now the gas travels toward the decompression unit.

    Step 3: The gas gets decompressed, chilled, and circulated towards the evaporator unit (a copper tube coil below the exhaust fan).

    Step 4: Finally, a blower forcefully blows water through the chilled copper tube and fins to raise its temperature slightly. Again, the refrigerant gas circulates towards the compressor for step 1.

    This procedure continues in a cyclic order in the heat pump to raise the pool water temperature in winter, and this is one of the most efficient solutions.

    An Example of a Pool Heat Pump

    Can a heat pump warm a whole house in winter?

    Theoretically, yes, but technically, it has to have a few criteria. Here’s the explanation.

    Heat pump capacity is measured in BTU. Generally, you will find a minimum size of 8000 BTU in the portable heat pump. Again, you will find up to 60,000 BTU of air conditioning system in the maximum range.

    Though for pool heating, a maximum of 140,000 BTU heat pump is available.

    Now do your calculation. 

    • 8000 BTU heat pump can handle a 100 square feet space.
    • 12000 BTU heat pump handles around 120~150 square feet of space.
    •  18000 BTU heat pump can heat up to 200 square feet of space.
    • 24000 BTU heat pump can heat up to 300 square feet of space.

    Thus, increasing the capacity will be able to handle a larger heating area.

    So, yes, a heat pump can heat your entire house in the winter, but you have to have the exact capacity to cover your whole house area.

    Note: Heat pumps are widely used worldwide as central air conditioning systems. So yes, they can heat the entire house. But the most efficient way of heating your home is using separate small (12K to 18K BTU) heat pumps for different rooms.

    How long should a heat pump run in winter?

    After setting your preferred temperature, you can run the heat pump as long as you want. 

    There won’t be any issue in more extended use cause when the room reaches its preset temperature; the heat pump will automatically turn off and turn on when the temperature falls by a degree.

    How do I know if my heat pump can work in the winter?

    The model or the packaging will note “Hot & Cool” clearly if the heat pump can do the job.

    In most cases, heat pumps are only used for air conditioning or cooling purpose. So in most cases, heat pumps are only capable of cooling. But a few heat pumps can deliver both hot and cold output.

    To ensure that your heat pump can deliver both hot and cold output, you must ensure the model or the packaging has noted the fact.

    Does a heat pump heat as well as a furnace?

    Yes, the heat pump can heat as well as a furnace and sometimes more efficiently than the furnace.

    In most cases, furnaces are fueled by gas, while heat pumps use electricity. Undoubtedly electricity is cheaper and cleaner than gas.

    You need to calculate the correct BTU to get the performance as good as a furnace from the heat pump.

    Do you still need a furnace with a heat pump?

    You might need a furnace for emergency purposes only. 

    If the ambient temperature falls below 32F, the heat pump can’t work much efficiently. Then the compressor gets an overload. So for those extremely chilled days, you might have a backup heating system like a furnace or electric heater.

    What temp should I set my heat pump in winter?

    70F to 80F, according to your comfort level.

    Though it’s not a matter, you might set any temperature you want for your comfort level. But the heat pump maintains 70F to 80F temperature more efficiently than a higher temperature.

    Do heat pumps dry out your house?

    No, a heat pump doesn’t dry your house; even no heater dries your house.

    Cold weather can hold a lower amount of humidity when you raise the room temperature, and the air’s moisture-holding capability increases. 

    So, the air takes the moisture from your body and other surfaces, and you feel dry. 

    You might use a humidifier to stay moist and any heating device to avoid getting dry.

    Questions About Using Heat Pumps in Winter

    1. Environment temperature range to keep the heat pump effective.

    Generally, for heating purpose heat pump’s efficiency starts dropping when the ambient temperature starts falling below 40F. Again for cooling purposes, heat pump performance decreases when the ambient temperature rises above 120F.

    This matter depends on the refrigerant that the heat pump uses.

    2. Why will my heat pump not run when it’s cold outside?

    If your outside temperature falls below 32F, your heat pump will struggle to produce enough heat. But it doesn’t stop working.

    3. Will freezing rain hurt a heat pump?

    No, it doesn’t hurt the heat pump, but you should use a shade at the top of the condenser unit to protect the inner components from snow.

    4. Are heat pumps worth it in cold climates?

    If the cold is above 40F, the heat pump is worth it. If the temperature drops more, then it won’t be efficient.

    5. What is cheaper to run a heat pump or gas furnace in winter?

    Of course, the heat pump. A gas furnace costs twice as much to run as an electric heat pump.

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